1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to an electric field read/write head, and more particularly, to an electric field read/write head which is capable of increasing the recording density of a conventional hard disk drive (HDD).
2. Description of the Related Art
An HDD is used as a computer's primary storage device, and operates by spinning a data recording medium and suspending a read/write head over the data recording medium to read and write data. A related art HDD normally uses magnetic writing. That is, the related art HDD uses a magnetic field to create a plurality of magnetic domains, which are magnetized in a first direction on the magnetic recording medium and in a second direction opposite to the first direction. Magnetic domains magnetized in the first and second directions correspond to data ‘0’ and data ‘1’, respectively.
HDDs employing this magnetic writing method have undergone tremendous increases in their writing densities over the last few decades. Horizontal magnetic writing on HDDs can produce a recording density of approximately 100 Gb/in2, and vertical magnetic writing on HDDs can produce a recording density of approximately 500 Gb/in2.
However, because a magnetic field has the basic shape of a loop, it is difficult for a magnetic read/write head to form a strong localized magnetic field. This basic limitation restricts the ability of the magnetic writing method to increase the recording density.
Accordingly, in order to increase the recording density of HDDs that have used the magnetic writing method, other writing methods must be considered.
Recently, research has been conducted into ferroelectric writing media, on which data is written using electric fields, and corresponding electric field read/write heads. The electric field writing method uses an electric field to form electric domains, which are polarized in a first direction and in a second direction opposite to the first direction on a ferroelectric surface. Electric domains polarized in the first and second directions correspond to data ‘0’ and data ‘1’, respectively. Based on the polarized direction of an electric domain, the resistance of the electric field read/write head above that domain changes, so that the data written in the electric domain can be discerned.
An electric field read/write head for this electric field writing method has a scanning probe with a field effect transistor channel configuration and a scanning probe with a resistive tip. When scanning probe microscope (SPM) technology is used as the scanning probe, a stronger and more localized electric field can be emitted in electric field writing, thereby increasing recording density to 1 Tb/in2 or higher.
However, in the electric field writing method based on SPM technology, a problem of friction and wear arises, due to contact between surfaces of a sharp probe and a recording medium. Also, in order to use a probe-type head to form a compact and large-capacity data storage device, several thousand probe arrays must be made, and the writing head must be linearly moved to precisely track over the thousands of probe arrays on the recording medium. Here, during a writing operation, signals must be applied separately to each probe, and during a reading operation, signals from the respective probes must be processed separately. These restrictive elements prohibit the realization of a compact and large capacity data storage device that uses electric field writing based on SPM technology.
Thus, new read/write heads that can overcome the problems of using probes need to be used, and an electric field writing-type data read/write device having a driving mechanism that is more secure and reliable is required.
While the above-described related art HDD has a driving mechanism that has been proven reliable over a long product lifespan, the mechanism is unsuitable for high-density data recording. On the other hand, while a data read/write device employing electric field writing based on SPM technology can produce a recording density of 1 Tb/in2 or higher, it is still difficult to manufacture and operate its head structure and driving system.
Therefore, it is necessary to develop an HDD driving system to which electric field writing is applied, without incurring development costs required to make an electrical field writing-type HDD, with both a reliable driving system and a recording density of at least 1 Tb/in2. To achieve such an HDD, an electric field read/write head which is capable of being suspended above a recording medium and appropriately performing reading and writing must first be developed.